Percutaneous uptake

Percutaneous uptake through the skin is possible -such as when using cosmetics, after-shave, gloss paints... 

Johanson G, Femstrom P. 1986. Percutaneous uptake rate of 2-butoxyethanol in the guinea pig. Scand J Work Environ Health 12(5) 499-503. 

Withey JR, Law FCP, Endrenyi L. 1993a. Percutaneous uptake, distribution, and excretion of pyrene in rats. J Toxicol Environ Health 40 601-612. 

The main barrier against percutaneous uptake of solvents are structures of the stratum comeum, especially intercellular lipids and fibrous keratin. Removal of lipids by polar solvents such as ethanol or hydration in the stratum comeum is associated with an increase of skin permeability. Defects or lack of stratum comeum that may occur in skin diseases, at particular skin locations such as hair folhcles or glandula regions enhance the percutaneous movement of solvents. The absorption through mucosa membranes is facilitated because of the lack of the stratum comeum. 

Chloroethanol, 2-butoxyethanol, carbon tetrachloride, 1,1,2-trichloroethane, DMF and dimethylsulfoxide gave rise to mortality in guinea pigs exposed percu-taneously (Wahlberg and Roman 1979). Fatalities in man have also been reported. An important aspect is thus that percutaneous absorption contributes to the total body burden, and there are strong motives to reduce percutaneous uptake as well as inhalation of solvents. 

Older literature indicated that using long-chained organic salts of divalent lead for various purposes, such as lubricants, would result in higher percutaneous uptakes than for simple divalent Pb salts. For example, Rastogi and Clausen (1976) reported that higher uptakes of Pb occurred when applied to rat skin as the naphthenate salt rather than in the acetate form. 

Local irritations do not occm except by fasciculation of xmderlying muscles after percutaneous uptake or miosis caused by excessive stimulation of muscarinic receptors on the papillary sphincter muscles, resulting from ocular exposure (Sidell and Borak, 1992 Dabisch et al., 2008). However, clinical symptoms related to massive restraints in motoric and respiratory abilities require the reduction of AChE activity by more than... 

---